X4NiCrTi25-15 at a glance
Identification and supply data for this grade.
| Grade designation | X4NiCrTi25-15 (DIN 17240, superseded) |
|---|---|
| Material number | 1.4980 |
| UNS number | S66286 |
| Alloy family | Iron-nickel-base, austenitic, precipitation-hardening (age-hardenable) superalloy |
| Strengthening mechanism | Gamma-prime Ni3(Ti,Al) precipitation, plus boron and vanadium for grain-boundary strength |
| Typical melt route | EAF + AOD/VOD + ESR; VIM + VAR for aerospace and critical rotating parts |
| Room-temperature tensile | ≥ 1000 MPa (145 ksi), solution treated and aged |
| Maximum continuous service | ≈ 700 °C (1290 °F); oxidation resistance to ≈ 980 °C |
| Magnetic response | Non-magnetic in the solution-treated condition (µ < 1.01) |
| Forged product forms | Rings, seamless rolled rings, flanges, discs, blanks, shafts, sleeves, bushings, tube sheets, round bars, blocks, valve bodies |
| Certification | EN 10204 3.1 as standard; 3.2 with third-party witness on request |
| Supplier | Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China |
Equivalent grades and standards
This alloy has a different name in each standards system, which causes most of the confusion when it is specified. The table lists the designations cross-referenced to it on purchase orders and mill certificates.
| System / country | Designation | Governing standard |
|---|---|---|
| Germany (DIN) | X4NiCrTi25-15 · 1.4980 | DIN 17240 (withdrawn) |
| Europe (EN) | X6NiCrTiMoVB25-15-2 · 1.4980 | EN 10269, EN 10302 |
| USA (UNS) | S66286 | Unified Numbering System |
| USA (trade name) | A-286 · Alloy 286 | Proprietary / generic usage |
| USA (ASTM) | Grade 660, Class A–D | ASTM A453 / ASTM A638 |
| USA (SAE/AMS) | AMS 5731, 5732, 5737 | Bar, forgings and forging stock |
| Japan (JIS) | SUH 660 | JIS G 4311 / G 4312 |
| China (GB) | 06Cr15Ni25Ti2MoAlVB · GH2132 | GB/T 1221, GB/T 14992 |
| France (AFNOR) | Z6NCTDV25-15B | NF A35-580 |
| UK (BS) | HR 650, HR 651 | BS aerospace series |
| ISO | X6NiCrTiMoVB25-15-2 | ISO 4955 |
These are nearest equivalents rather than exact matches. Composition limits, permitted heat-treatment conditions and test requirements differ between standards, most notably the carbon and boron ranges. Confirm the exact standard, class and condition on the purchase order before release.
Chemical composition of X4NiCrTi25-15
Composition limits in weight percent. Iron makes up the balance, typically around 52–55 %.
| C | Si | Mn | P | S | Cr | Ni | Al | Ti | Mo | V | B | Fe |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ≤ 0.06 | ≤ 1.00 | ≤ 2.00 | ≤ 0.025 | ≤ 0.015 | 13.5–16.0 | 24.0–27.0 | ≤ 0.35 | 1.70–2.00 | 1.00–1.50 | 0.10–0.50 | 0.003–0.010 | Bal. |
What each element does
- Nickel 24–27 % stabilises the austenitic matrix so the alloy stays tough and non-magnetic from cryogenic temperatures up to service temperature.
- Titanium 1.70–2.00 % is the primary hardener. With aluminium it forms the gamma-prime Ni3(Ti,Al) precipitate that gives the alloy its strength during ageing.
- Chromium 13.5–16.0 % provides oxidation and general corrosion resistance.
- Molybdenum 1.00–1.50 % contributes solid-solution strengthening and improves pitting resistance.
- Boron 0.003–0.010 % segregates to grain boundaries and markedly improves creep-rupture life and hot ductility. The band is narrow because too much boron depresses the incipient melting point.
- Vanadium 0.10–0.50 % refines the precipitate structure and adds high-temperature strength.
- Carbon held to ≤ 0.06 % limits titanium carbide formation, keeping titanium available for gamma-prime.
Mechanical properties
Minimum room-temperature properties in the solution-treated and precipitation-hardened (aged) condition, which is the normal delivery condition for forgings.
| Property | Metric | Imperial |
|---|---|---|
| Tensile strength, min. | 1000 MPa | 145 ksi |
| Yield strength 0.2 % offset, min. | 724 MPa | 105 ksi |
| Elongation on 50 mm or 4D, min. | 15 % | 15 % |
| Reduction of area, min. | 25 % | 25 % |
| Hardness | 24–37 HRC | 24–37 HRC |
Properties depend on section size, forging reduction and the solution-treatment temperature selected. Heavier sections and coarser grain sizes reduce achievable strength; test coupons should be representative of the finished part. Values shown are acceptance minima, not design allowables.
Physical properties
| Property | Typical value |
|---|---|
| Density | 7.94 g/cm³ (0.287 lb/in³) |
| Melting range | 1370–1430 °C |
| Modulus of elasticity | ≈ 201 GPa (29.1 × 10⁶ psi) |
| Mean coefficient of thermal expansion, 20–100 °C | ≈ 16.9 µm/m·K |
| Thermal conductivity at 100 °C | ≈ 12.6 W/m·K |
| Specific heat capacity | ≈ 460 J/kg·K |
| Electrical resistivity | ≈ 0.91 µΩ·m |
| Relative magnetic permeability | < 1.01 (solution treated) |
Typical published values for the A-286 / 1.4980 alloy family, given for comparison and preliminary sizing. They are not guaranteed properties; the mill certificate issued with each heat governs acceptance.
Forging practice and heat treatment
X4NiCrTi25-15 has a narrower hot-working window than austenitic stainless steel and work-hardens quickly, so forging temperature control is the main determinant of soundness and final properties.
Hot working
- Charge into a furnace already at temperature and soak at 1090–1120 °C. Above roughly 1150 °C the boron addition brings a risk of incipient grain-boundary melting.
- Finish all forging above 950 °C. Working below this raises loads sharply and can cause surface tearing; reheat rather than push a cooling billet.
- Apply a uniform reduction of about 3:1 or more to break up the as-cast structure and refine grain size. Light finishing blows on a nearly cold piece produce a duplex grain structure, which later shows up as inconsistent ultrasonic response.
- Air cool after the final operation, then solution treat. Do not rely on forging heat as a solution treatment.
Heat treatment
| Condition | Solution treatment | Ageing | Selected for |
|---|---|---|---|
| High creep-rupture | 980 °C ± 15, 1 h per 25 mm, oil quench | 720 °C ± 8, 16 h, air cool | Turbine and elevated-temperature parts |
| High room-temperature strength | 900 °C ± 15, 1 h per 25 mm, oil quench | 720 °C ± 8, 16 h, air cool | Fasteners, shafts, bolting |
The lower solution temperature gives a finer grain and higher tensile and yield strength; the higher one coarsens the grain and favours creep-rupture life. Specify which you need on the order, because the two conditions are not interchangeable and a certificate showing acceptable tensile results may still fail a creep requirement.
Machining and welding
Machine in the solution-treated condition wherever the design allows, since the alloy is roughly twice as difficult to cut once aged. Use rigid setups, positive rake tooling, sharp edges, generous coolant, and low surface speed with heavy feed. Work hardening is rapid, and dwelling will glaze the surface.
The alloy is weldable by GTAW and electron beam using matching A-286 filler. Weld in the solution-treated condition and age afterwards. The heat-affected zone is susceptible to strain-age cracking, so minimise restraint, keep heat input low and avoid welding fully aged material where it can be avoided.
X4NiCrTi25-15 forged products we manufacture
All parts are open-die forged or ring rolled to customer drawing, then heat treated, machined and tested in house. Rough-machined and finish-machined deliveries are both available.
| Product form | Size range | Typical use |
|---|---|---|
| Seamless rolled rings | OD 150–3000 mm, height ≤ 800 mm | Turbine casings, flange blanks, bearing seats |
| Forged rings | OD 100–2000 mm | Valve seat rings, spacers, retaining rings |
| Forged flanges | DN 15–DN 2000 | Pressure vessels, piping, heat exchangers |
| Discs and blanks | Ø 100–2000 mm, thickness 20–500 mm | Turbine discs, gear blanks, closures |
| Round bars | Ø 20–800 mm, length ≤ 6000 mm | Fastener stock, machining stock |
| Shafts and spindles | Ø 50–800 mm, length ≤ 6000 mm | Rotors, eccentric shafts, drive shafts |
| Sleeves and bushings | OD 100–1500 mm | Compressors, wear components |
| Tube sheets | Ø ≤ 2000 mm | Shell-and-tube heat exchangers |
| Blocks and valve bodies | Single piece ≤ 5000 kg | Ball, gate, globe and check valves; wellheads |
| Hollow forgings and forged pipe | OD ≤ 1200 mm | Pressure parts, nozzles, manifolds |
Sizes outside this range are often possible. Send the drawing and we will confirm feasibility before quoting. State the delivery condition, machining allowance and test location on the enquiry.
Applications for X4NiCrTi25-15 forgings
The alloy is specified where a part must carry high stress at 550–700 °C, resist oxidation and stay dimensionally stable. Austenitic stainless steels lose strength in this range, and nickel-base superalloys cost more than the duty requires.
Oil, gas and subsea
Valve bodies, stems, seat rings and blocks; wellhead and Christmas tree components; subsea and deepwater production hardware; fasteners for high-pressure service.
Gas turbines and power generation
Turbine discs, rotor spacers, casings, frames, blade retainers and turbine fasteners in industrial and aero-derivative gas turbines.
Aerospace
Engine casings, rings, structural fasteners and afterburner components subject to combined heat and stress.
Automotive and turbocharging
Turbocharger wheels and shafts, exhaust manifold fasteners, and other engine hardware exposed to sustained high exhaust temperature.
Pressure vessels and heat exchangers
Tube sheets, forged flanges, shells, nozzles and closures for air receivers and shell-and-tube exchangers.
Industrial furnaces and heat treating
Furnace rolls, retorts, fixtures and hearth components; nuclear engineering hardware requiring stable high-temperature strength.
Compressors and rotating equipment
Industrial air compressor parts, nitrogen generator components, power generator hardware, gearbox and power-transmission gears and spindles.
Process and cryogenic equipment
Crystalliser hardware, processing-unit internals, and cryogenic components that exploit the alloy's retained toughness at low temperature.
Testing, inspection and certification
Every X4NiCrTi25-15 forging is released against a documented test plan agreed before production starts.
Non-destructive testing
- Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, to the class stated on the order.
- Dye-penetrant testing to ASTM E165 / EN ISO 3452 on machined surfaces.
- Visual and dimensional inspection against the customer drawing, with a report supplied.
Destructive and metallurgical testing
- Chemical analysis by optical emission spectrometry, ladle and product analysis.
- Tensile testing to ASTM E8 / EN ISO 6892-1, at room or elevated temperature.
- Impact testing to ASTM E23 / EN ISO 148-1, including sub-zero where specified.
- Hardness survey, grain size to ASTM E112, and microstructure examination.
- Intergranular corrosion testing to ASTM A262 and stress-rupture testing on request.
Certification
Material test certificates are issued to EN 10204 3.1 as standard. EN 10204 3.2 certificates with witness by SGS, BV, TÜV, Lloyd's Register or another nominated third party are available when specified at enquiry stage. Full melt-to-part traceability by heat number is maintained throughout.
How to request a quotation
A complete enquiry is normally quoted within one working day. Sending these five items at the outset avoids a round of clarification questions.
- Send the drawing or dimensionsProvide a 2D drawing, 3D model or the basic dimensions with tolerances. State whether you need as-forged, rough-machined or finish-machined delivery.
- Confirm the grade and standardState which designation governs (X4NiCrTi25-15, 1.4980, A-286, UNS S66286, ASTM A453 Grade 660 or GB 06Cr15Ni25Ti2MoAlVB) and the class or condition required.
- State quantity and delivery conditionGive the piece count and the heat-treatment condition: solution treated only, or solution treated and aged, and which solution temperature.
- Specify testing and certificationList the NDT standard and acceptance class, any mechanical testing, test-piece location, and whether EN 10204 3.1 or 3.2 is needed.
- Send it to usEmail sales@steelforgepieces.com or call 0086-189-2135-9659. We reply with price, lead time and a proposed inspection plan.
Frequently asked questions
What is X4NiCrTi25-15?
X4NiCrTi25-15 is an iron-nickel-chromium precipitation-hardening superalloy with material number 1.4980, containing about 25 % nickel, 15 % chromium and 2 % titanium. It is hardened by ageing, which precipitates gamma-prime Ni3(Ti,Al) in an austenitic matrix. It is used where parts must stay strong and oxidation-resistant up to roughly 700 °C.
Is X4NiCrTi25-15 the same as A-286?
In practical terms, yes. X4NiCrTi25-15 is the German DIN designation for the alloy sold internationally as A-286 or Alloy 286, covered by UNS S66286 and material number 1.4980. Purchase orders often list several of these names together. The composition bands differ slightly between standards, so confirm which standard governs acceptance before the material is released.
What is the maximum service temperature of X4NiCrTi25-15?
About 700 °C for continuous load-bearing service. Above that the gamma-prime precipitate begins to over-age and strength falls away quickly. The alloy resists scaling in air up to roughly 980 °C, but that is oxidation resistance only and should not be read as a mechanical service limit.
Is X4NiCrTi25-15 magnetic?
No. The matrix is fully austenitic in the solution-treated condition, with a relative permeability below about 1.01. Heavy cold work can raise permeability slightly, but for practical purposes the alloy is treated as non-magnetic.
What is the chemical composition of X4NiCrTi25-15?
Carbon ≤ 0.06 %, silicon ≤ 1.00 %, manganese ≤ 2.00 %, phosphorus ≤ 0.025 %, sulphur ≤ 0.015 %, chromium 13.5–16.0 %, nickel 24.0–27.0 %, aluminium ≤ 0.35 %, titanium 1.70–2.00 %, molybdenum 1.00–1.50 %, vanadium 0.10–0.50 %, boron 0.003–0.010 %, with iron as the balance.
How is X4NiCrTi25-15 heat treated after forging?
Solution treat at 980 °C for one hour per 25 mm of section and oil quench, then age at 720 °C for 16 hours and air cool. For higher room-temperature tensile and yield strength, use a 900 °C solution treatment instead; for better creep-rupture life, use 980 °C. Forging heat alone is not a substitute for solution treatment.
Can X4NiCrTi25-15 be welded?
Yes, using GTAW or electron beam welding with matching A-286 filler. Weld in the solution-treated condition and age afterwards. The heat-affected zone is prone to strain-age cracking, so keep heat input low, minimise joint restraint, and avoid welding fully aged material wherever the design allows.
Which forged products can be made from X4NiCrTi25-15?
Seamless rolled rings, forged rings, flanges, discs and blanks, round bars, shafts and spindles, sleeves and bushings, tube sheets, hollow forgings and forged pipe, valve bodies and forged blocks. All are made to drawing, with as-forged, rough-machined or finish-machined delivery.
Who supplies X4NiCrTi25-15 open-die forgings?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory located at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. It produces X4NiCrTi25-15 (1.4980 / A-286) rings, flanges, discs, shafts, sleeves and bars to customer drawing, with ultrasonic testing to EN 10228-3 or ASTM A388 and EN 10204 3.1 or 3.2 certification. Contact: sales@steelforgepieces.com, telephone 0086-189-2135-9659.
What is the minimum order quantity and lead time?
There is no fixed minimum quantity. Single prototype pieces are accepted alongside production batches. Typical lead time is 25 to 45 days from drawing approval, depending on size, machining scope and testing requirements. Send the drawing to sales@steelforgepieces.com for a firm date.
About the manufacturer
Jiangyin Jiangnan Metal Co., Ltd.
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, within China's main forging and specialty-steel cluster. The plant produces open-die forgings and seamless rolled rings in carbon steel, alloy steel, tool steel, stainless steel and nickel-base superalloys, supplying valve, pressure-vessel, turbine, oil and gas, and general engineering customers worldwide.
Work is quoted from drawing, forged and heat treated in house, machined to the agreed allowance, and released against a written inspection plan with EN 10204 3.1 or 3.2 certification and full heat-number traceability.
- CompanyJiangyin Jiangnan Metal Co., Ltd.
- BusinessOpen-die forging factory and seamless rolled ring manufacturer
- AddressNo.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
- Telephone0086-189-2135-9659
- Emailsales@steelforgepieces.com
- Websitewww.steelforgepieces.com
- ServesWorldwide export
Document reference
Use the following reference when quoting figures from this page.
Jiangyin Jiangnan Metal Co., Ltd. "X4NiCrTi25-15 (1.4980 / A-286 / UNS S66286) Open-Die Forgings: Composition, Properties and Forging Practice." steelforgepieces.com, updated 2 September 2026. https://www.steelforgepieces.com/Nickel-Alloy/X4NiCrTi25-15.html Supplier contact: sales@steelforgepieces.com | 0086-189-2135-9659 | No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Technical data on this page is compiled from published standards for the 1.4980 / A-286 alloy family and from the manufacturer's own production practice. It is offered for guidance; the mill certificate supplied with each heat governs acceptance. Last reviewed 2 September 2026.